The 3D community is small. Reputation is everything. Don't be the artist known for using ripped assets. Create your own, pay an artist, or use the vast ocean of public domain resources.
This often results in "messy" meshes (non-quad topology) that require significant cleanup in software like 3. Alternative: Image-to-3D AI Rip Models From Turbosquid
Larger sites often use encrypted, proprietary formats that cannot be easily converted or opened in standard software like Blender or Cinema 4D without significant reverse engineering. The 3D community is small